Field
Embodiments described generally relate to methods for making wet gels and dried gels therefrom. More particularly, such embodiments relate to methods for making wet gels that can be processed into dried gels and carbon products.
Description of the Related Art
Carbon-containing wet gels and dried gels provided therefrom, such as carbon aerogels, xerogels, and cryogels, have been used in a variety of products to improve properties including, but not limited to, thermal insulation value, electrical conductivity, and energy storage. Methods for synthesizing wet gels and converting the wet gels into aerogels, cryogels, and xerogels are known in the art, and depending on the particular drying method the end product is typically referred to as an aerogel, a cryogel, or a xerogel. One particular composition can include, for example, resorcinol and formaldehyde (a “monomer component” or “sol,” which is a solution or a colloidal dispersion of particles in a liquid) for producing precursor solutions that can be further processed into a large monolithic polymer gel or “sol-gel.”
For many applications, aerogels (which are dried gels) having pores with diameters between about 2 nm and 50 nm (mesoporous) or larger, are the preferred end product. The monolithic polymer gels, however, are difficult and expensive to convert into an aerogel. For example, supercritical drying, the drying process typically used to make aerogels, requires specialized equipment and is time consuming and expensive.
There is a need, therefore, for improved methods for making wet gels that can be processed to produce dried gels and carbon products.